Alert archive / Arkansas / Mesoscale Discussions in 2011
Mesoscale Discussion 914
The Storm Prediction Center issued this mesoscale discussion at May 23, 2011, 8:55 PM CDT for 16 counties in Arkansas. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- May 23, 2011, 8:55 PM CDT (01:55 UTC)
- Expired
- May 23, 2011, 10:30 PM CDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
Counties Conway County, AR, Faulkner County, AR, Garland County, AR, Johnson County, AR, Logan County, AR, Lonoke County, AR, Montgomery County, AR, Perry County, AR, Pope County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Searcy County, AR, Van Buren County, AR, White County, AR, Yell County, AR
The radar
The Little Rock radar (KLZK), 71 km from the middle of the area, began a volume at 01:56 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Springfield, MO (KSGF), launched 00:00Z, 1.9 hours before the alert went out and 201 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 23 J/kg
- Mixed-layer CIN
- -417 J/kg
- Mixed-layer LCL
- 1542 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- -138 m²/s²
- 0-3 km storm-relative helicity
- -19 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
348
ACUS11 KWNS 240155
SWOMCD
SPC MCD 240155
ARZ000-240330-
MESOSCALE DISCUSSION 0914
NWS STORM PREDICTION CENTER NORMAN OK
0855 PM CDT MON MAY 23 2011
AREAS AFFECTED...N-CNTRL THROUGH CNTRL AR
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 240155Z - 240330Z
STORMS WILL LIKELY CONTINUE SEWD INTO CNTRL AR DURING THE EVENING
WITH A THREAT FOR PRIMARILY ISOLATED DAMAGING WIND AND LARGE HAIL.
WW WILL PROBABLY BE NEEDED PRIOR TO 03Z FOR A PORTION OF N-CNTRL
THROUGH CNTRL AR.
STORMS HAVE EVOLVED INTO A FORWARD PROPAGATING MCS FROM ERN OK INTO
EXTREME NWRN AR MOVING SEWD AT 30-35 KT. AN EXTENSIVE CONVECTIVE
OUTFLOW BOUNDARY EXTENDS FROM THE TN VALLEY WWD THROUGH S-CNTRL AR
INTO E-CNTRL OK WHERE IT INTERSECTS THE SQUALL LINE. THE 00Z LITTLE
ROCK SOUNDING WAS SAMPLED NORTH OF THE OUTFLOW BOUNDARY AND SHOWS A
VERY MOIST BOUNDARY LAYER ALONG WITH 2500 J/KG MLCAPE...STEEP LAPSE
RATES AND 47 KT SFC-6 KM SHEAR. CURRENT THINKING IS THAT THE
PERSISTENT SLY LLJ WILL MAINTAIN INFLUX OF HIGHER THETA-E AIR FROM
THE WARM SECTOR AND HELP TO SUSTAIN A FORWARD PROPAGATING SYSTEM
INTO CNTRL AR. BOWING SEGMENTS WITH DAMAGING WIND APPEARS PROBABLE
ALONG WITH ISOLATED HAIL.
..DIAL.. 05/24/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LZK...TSA...
LAT...LON 35889343 35939265 35659208 35029150 34319184 34479374
34949414 35889343SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 23, 9:42 PM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Cleburne, Conway, Crawford, Faulkner, Franklin and 21 more | 6 hr |
| May 24, 2:08 AM CDT | Mesoscale Discussion | SPC | Arkansas, Clark, Cleveland, Crawford, Dallas, Franklin and 21 more | 97 min |
Nearby
Mesoscale Discussions in Arkansas, 2011Every mesoscale discussion in 2011
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.